Method and means for turning tubular articles at a circular knitting machine



c. B. BOYLEN 3,296,838 METHOD AND MEANS FOR TURNING TUBULAR ARTICLES AT A Jan. 10, 1967 CIRCULAR KNITTING MACHINE Filed Sept. 5, 1963 4 Sheets-$heet l INVENTOR.

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METHOD AND MEANS FOR TURNING TUBULAR ARTICLES AT A CIRCULAR KNITTING MACHINE Filed Sept. 5, 1963 4 Sheets$heet 2 f'ign 4770 NEWS INVENTOR Jan. 10, 1967 r c. B. BOYLEN 3,296,838

METHOD AND MEANS FOR TURNING TUBULAR ARTICLES AT A CIRCULAR KNITTING MACHINE Filed Sept. 5, 1963 4 Sheets-Sheet 3 W I TTTTITTTHI 4 IN VENTOR.

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METHOD AND MEANS FOR TURNING TUBULAR ARTICLES AT A CIRCULAR KNITTING MACHINE 4 Sheets-Sheet 4 Filed Sept. 5, 1965 INVENTOR. CZAAE/VCfi' 6. Barbi/V BY 3 1:. iii/c 4770 IYEKS United States Patent METHGD AND MEANS FOR TURNING TUBU- LATE ARTICLES AT A CHRCULAR KNTTTING MACHHNE Clarence B. Eoylen, High Point, N.C., assignor to Russell Hosiery Mills, lnc., Star, N.C., a corporation of North Carolina Filed Sept. 3, 1963, Ser. No. 305,929

15 Claims. (Cl. 66-149) The present invention relates to a method and means for turning tubular knit articles at a circular knitting machine upon completion of each knitting cycle in a simple and reliable manner without affecting the normal knitting operation or timing of the machine and using a simple and inexpensive turning mechanism that is easily operated and can be readily attached to a knitting machine with little or no modification of the machine.

In the present invention turning is accomplished by suction in a turning tube that extends within the needle cylinder and has an open turning end adjacent the knitting end of the needle cylinder. A slidable extension tube is mounted on this turning tube for positioning thereon to extend beyond the open turning end to prevent the articles from entering the turning tube as the articles are being knit, and is slidable to a retracted position away from the turning end upon completion of each knitting cycle to permit the suction in the turning tube to turn the completed articles into the turning end thereof, with the suction discharging the turned articles through the turning tube.

In the preferred embodiment, the present invention is used to particular advantage in turning articles, such as socks, having elastic portions that are knit first in the knitting cycle. In knitting this type of article, the elastic of the first-knit portion draws the fabric radially inward as knitting progresses, and the slidable extension tube, in raised position, receives the fabric as it draws radially inward and prevents it from entering the turning tube. Subsequently, the slidable tube serves as a means for pulling the fabric down into the needle cylinder away from the turning end of the turning tube to position the article for turning after knitting is completed, by sliding downward on the turning tube and drawing the elastic fabric engaged thereon downwardly with it. Ultimately, the sliding extension or pull-down tube slides out of the fabric, leaving the article in proper position for turning at the end of the knitting cycle.

The features and advantages of the present invention are herein disclosed in relation to the preferred embodiment described below and illustrated in the accompanying drawings, in which:

FIG. 1 is an elevational view of the preferred embodiment of the turning means of the present invention mounted for operation on a circular knitting machine, only the pertinent elements of which knitting machine are illustrated herein;

FIG. 2 is a vertical sectional view of the embodiment of FIG. 1, taken along line 22 of FIG. 5, and showing the pull-down tube in its initially raised position;

FIG. 3 is an enlarged view similar to FIG. 2, showing the pulldown tube in an intermediate article pull-down position;

FIG. 4 is a view similar to FIG. 3, showing the pulldown tube in its retracted position and the article being turned into the turning tube;

FIG. 5 is a plan view of the embodiment of FIG. 1; and

FIG. 6 is a horizontal sectional view taken along line 66 of FIG. 2.

The article turning means 10 of the preferred embodiment is shown attached to a conventional circular knitting 3,296,838 Patented Jan. 10, 1967 machine 12 that operates to knit tubular fabric, such as socks, b manipulation of the needles 14 carried on a rotatable needle cylinder 16 in relates to a dial cap 18 immediately above the needle cylinder. The needle cylinder 16 is supported on a bearing plate 20 (which could be a ball bearing ring), which is mounted on a fabric raising tube 22 supported in the bed plate 24 and on a shiftable bracket 26 by a flange support 28. These are all elements of a conventional circular knitting machine, the other elements of which need not be shown as they are well-known to those skilled in the art, and do not constitute a part of the present invention, Which could be adapted to various types of knitting machines.

The turning means 10 has a cylindrical turning tube 30 extending concentrically within the needle cylinder 16 and fabric tube 22 and mounted in a pair of vertically spaced support plates 32 and 34 secured in the 'bottom of the fabric tube 22 to support and stabilize the turning tube.

The turning tube 30 is of substantially lesser diameter than the needle cylinder 16 to provide an annular fabric take-down space 36 therebetween, and has an upper, open, fabric turning, end 38 slightly below the upper knitting end of the needle cylinder 16 for drawing thereinto the tubular knit articles as they drop from the needles 14 at the end of each knitting cycle, as will be described hereinbelow.

The turning tube 30 extends downwardly below the fabric tube 22 to a T connection in a discharge tube 40, which has one end 42 connected to a supply line 44 of an air pressure system and extends to a discharge end 46 opening diagonally upwardly into the side of a vertical collection tube 50 spaced laterally from the fabric tube 22 and having a perforated top plate 52 that allows air to flow therethrough, but retains articles discharged from the discharge tube 40 into the collection tube. The collection tube 50 has an open bottom end 54 to which a collection bag 56 is removably attached to collect the articles as they drop from the collection tube 50.

Slidably mounted on the turning tube 30 within the needle cylinder 16 and fabric tube 22 is a pull-down tube 58 that has at its upper end 60 an outwardly extending, upwardly tapering, fabric receiving flange 62. The pulldown tube 58 is freely supported on an annular bearing ring 64 surrounding the turning tube 30 and carried on a support yoke 66 extending from the upper end 68 of a vertical piston rod 70 that extends into a vertical air cylinder 72 threadably secured to the upper support plate 32 and extending downwardly therefrom through the lower support plate 34 to an air supply line 74 of the aforementioned air pressure system. The piston rod 70 is moved by air pressure in the cylinder 72 from a retracted position (FIGS. 3 and 4) at the upper support plate 32 to a projected position (FIG. 2) at which its upper end 68 abuts a resilient stop plug 76 supported in a bracket 78 secured to the inside of the fabric tube 22 adjacent the needle cylinder 16 to position the pull-' down tube 58 supported on the yoke 66 with its flanged upper end 60 extending beyond the turning end 38 of the turning tube 30 and abutting the dial cap 18 to receive fabric during the knitting cycle and prevent the fabric from entering the turning tube 30 (FIG. 2).

Reciprocation of the piston rod 70 is controlled by a conventional valve mechanism 80 in the air supply line 74, which also includes a conventional reducer 82 to reduce the line pressuer from the high pressure necessary in the discharge tube 40 for turning articles intothe turning tube 30 to the lesser pressure needed to operate the piston rod 70. Also, a conventional bleeder valve 84 is provided at the top of the air cylinder 72 to facilitate reciprocation of the piston rod 70 by allowing air to escape above the piston (not shown) during upward movement of the piston rod 70 and by allowing air to enter during retraction of the piston rod.

The valve mechanism 80 and reducer 82, as well as the control valve 86 in the supply line 44 leading to the discharge tube 40, are shown diagrammatically as they may be of any well-known conventional construction. The valve mechanism 80 and control valve 86 are operated in any conventional manner from the knitting cycle control mechanism, such as a main drum, of the knitting machine 12.

When the slidable pull-down tube 58 is held in its raised, article receiving position (FIG. 2) by the raised piston rod 70, the portion of the fabric knit at the beginning of the knitting cycle is received under the flange 62 and the pull-down tube is free to rotate with the fabric due to its free support on the bearing ring 64, thus avoiding twisting of the fabric on the tube, which could cause the fabric to move up on the tube and become dislodged therefrom. The flange 62 also serves to retain the fabric on the tube.

When knitting has progressed sufficiently to provide a length of fabric that can be pulled away from the turning end 38 of the turning tube 30 so that the fabric will not enter the turning tube upon retraction of the pull-down tube 58, the piston rod 70 is retracted and the pull-down tube 58 begins to drop, but the fabric remains under the flange 62 and is pulled down thereby away from the turning end 38 of the turning tube with the pull-down tube 58 thereby hanging freely in the fabric (FIG. 3) for rotation therewith so that the fabric will not twist up and off the tube. The weight of the pull-down tube 58 and the vibration during operation eventually cause the fabric to slide over the pull-down tube flange 62, releasing the tube to fall to retracted position (FIG. 4) so as not to interfere with turning of the article into the turning tube 30 at the end of the knitting cycle. The free hang of the pulldown tube 58 in the fabric and the gradual sliding of the tube through the fabric eliminates any tendency of the fabric, particularly elastic fabric, to snap upwardly when the tube drops, as might occur if the pull-down tube were retracted by some positive mechanism.

Release of the pull-down tube 58 from the fabric is facilitated by forming the turning tube 30 with an intermediate portion 88 of reduced diameter spaced from the turning end 38 thereof. This reduced diameter portion permits substantial vibration of the pull-down tube when it progresses downwardly with the fabric to this portion. This vibration readily shakes the pull-down tube 58 from the fabric, allowing the tube to drop to retracted position and freeing the fabric for subsequent turning. This reduced diameter portion 88 also serves to accommodate the relatively tight, elastic, first-knit fabric portion during continued knitting without twisting of the fabric as may occur if the relatively large diameter of the turning end 38 were continued throughout the length of the turning tube 30.

The turning end 38 and the upper portion 90 of the turning tube above the reduced intermediate portion 88 are of enlarged diameter to facilitate turning therein-to of the initial bulk of the article and avoid binding of the article such that'it will not turn. This enlarged diameter portion 90 extends downwardly a distance sufficient to space the first knit portion of the fabric well below the turning end 38 before the pull-down tube slides out of the fabric by vibration caused by the reduced diameter of the intermediate portion 88.

The lower portion 92 of the turning tube 30 is also of enlarged diameter to center the pull-down tube 58 in proper retracted position ready for the next raising thereof.

In a typical operation in which socks with elastic tops are knit with the elastic portions knit during the first portion of the knitting cycle, the valve mechanism 80 is actuated at the beginning of the cycle, preferably when the machine indexes from the makeup to the elastic top, to introduce air to the cylinder 72 to raise the pull-down tube 58 to its receiving position covering the turning end 38 of the turning tube 30 and hold the tube in this position until enough courses are knit to assure receipt of the fabric under the pull-down tube flange 62 (FIG. 2). The valve mechanism then closes the air supply, preferably as the machine indexes from the top to the leg, to allow the piston rod 70 to retract and to allow the pull-down tube 58 to hang freely in the elastic top (FIG. 3). Retraction of the rod 70 results from air leakage provided in the cylinder 72 or by using a valve of a conventional type opening to the atmosphere to permit escape of air from the cylinder. As knitting progresses, the pull-down tube 58 reaches the intermediate turning tube portion 88 of reduced diameter and vibrates so as to shake out of the elastic top and drop to retracted position. Knitting continues through the leg, heel, foot, toe and tip portions of the sock, and the completed sock is cut-off or otherwise dropped from the needles 14. During cut-off, the control valve 86 is opened slightly to allow a slight flow of air through the discharge tube 40, creating a slight suction at the turning end 38 of the turning tube and thereby assuring proper positioning of the sock for turning. When the cut-off is complete, the control valve 86 opens fully to allow a substantial flow of air through the discharge tube 40 sufiicent to create enough suction in the turning tube 30 to draw the sock thereinto for turning and discharge through the turning tube and discharge tube into the collection tube 50. The control valve 86 is then closed and the discharged sock drops into the collection bag 56.

The particular timing of the valve mechanism 80 and control valve 86 in relation to the knitting cycle may be varied as desired to obtain best results for particular sizes and shapes of articles being knit.

In a typical installation in which socks with elastic tops are knit on a circular knitting machine having a needle cylinder with an inner diameter of 3%", the turning tube 30 is made of stainless steel tubing 4; thick and 24" long, with its turning end A" below the top of the needle cylinder. The enlarged upper portion 90 is 3" long and 1 /8" in diameter; the reduced intermediate portion 88 is 15" long and 1%" in diameter; and the enlarged lower portion 92 is 6" long and 1%" in diameter. The pull-down tube 58 is made of aluminum tubing thick. It has an outer diameter of 1 and an inner diameter of 1 7 and the flange 62 has an outer diameter of 2". The piston rod 70 is a A" metal rod. The air cylinder 72 is 1%" in diameter and 20" long. The air pressure supply is a minimum of psi. with this pressure being the minimum in the discharge tube 40. The reducer 82 reduces the pressure in the air cylinder 72 to 8 psi. These dimensions and specifications are set out simply for exemplification, and may be varied as desired depending upon various operating conditions and structures.

The invention has been described in detail above for purposes of illustration only, and is not intended to be limited by this description or otherwise except as defined in the appended claims.

I claim:

1. A method of turning tubular articles at a circular knitting machine using a stationary turning tube having an open turning end in the needle cylinder adjacent the knitting end thereof and an extension tube slidable on said stationary turning tube, said method comprising positioning said extension tube in a raised position extending beyond the turning end of the turning tube during the initial portion of each knitting cycle to prevent the firstknit portion of the article from entering said turning end, allowing the extension tube to slide downwardly away from said turning end before completion of the knitting cycle with said first-knit portion below the turning end, creating a suction in said turning tube at the end of each knitting cycle to turn articles into the turning tube.

2. A method of turning tubular articles at a circular knitting machine according to claim 1 and characterized further by application of a slight suction to said turning tube immediately prior to completion of each knitting cycle to assure positioning of the completed article for subsequent turning.

3. A method of turning tubular articles, such as sock-s, at a knitting machine, wherein the articles have elastic portions that are knit first in the knitting cycle, said method using a stationary turningtube having an open turning end in the needle cylinder adjacent the knitting end thereof and a pull-downtube slidable and rotatable on said stationary turning tube, said method comprising positioning said pull-down tube in a raised position extending beyond the turning end of said turning tube during the initial portion of each knitting cycle to receive the firstknit elastic portion and prevent it from entering said turning tube, allowing said pull-down tube to slide downward- 1y on said turning tube to pull said first-knit elastic portion downwardly away from said turning end while rotating therewith about said stationary turning tube and ultimately to slide through said first-knit elastic portion, creating a suction in said turning tube at the end of each knitting cycle to turn articles into the turning tube.

4. A method of turning tubular articles at a circular knitting machine according to claim 3 and characterized further in that said pull-down tube is allowed to hang freely in said first-knit elastic portion as it slides downwardly therethrough against the restraint thereof, thereby rotating with said elastic portion as it gradually pulls said elastic portion away from said turning end.

5. A method of turning tubular articles at a circular knitting machine according to claim 4 and characterized further by vibrating said pull-down tube after it slides away from said turning end to facilitate release of the pull-down tube from said elastic portion.

6. In a circular knitting machine, means extending within the needle cylinder for turning tubular articles at the completion of each knitting cycle, said turning means comprising a stationary turning tube extending in said needle cylinder in spaced relation thereto and having an open turning end adjacent the knitting end of the needle cylinder, an extension tube slidably mounted on said stationary turning tube for sliding between an article engagmg position at which it extends beyond said turning end of the turning tube to prevent articles from entering said turning tube without turning as they are being knit and a retracted position away from said turning end to permit articles to turn into said turning end at the completion of kn tting, means for moving said extension tube to said article engaging position in timed relation to the knitting cycle, and means for creating a suction in said turning tube to turn articles thereinto at the end of each knittin cycle. a

7. In a circular knitting machine, article turning means according to claim 6 and characterized further in that said extension tube has an outwardly extending flange under which the first-knit portion of articles are received when said extension tube is in said article engaging position and which pulls said first-knit portions away from said turning end as the extension tube slides to retracted posit on, and said extension tube is rotatable about said stationary turning tube for rotation with said articles durmg knitting.

d. In a circular knitting machine for knitting tubular articles, such as socks, having elastic portions that are knit first in the knitting cycle, means extending within the needle cylinder for turning the tubular articles at the end of each knitting cycle, said turning means comprismg a stationary turning tube extending in said needle cylinder in spaced relation thereto and having an open turning end adjacent the knitting end of the needle cylinder, a pull-down tube slidably mounted on said stationary turning tube for sliding between an article engaging position at which it extends beyond said turning end of the turning tube to receive the first-knit elastic portions of the articles and prevent them from entering said turning tube as the articles are being knit and a retracted position away from said turning end to permit articles to turn into said turning end at the completion of knitting, said pull-down tube pulling the elastic portions of the articles away from the turning end as it moves to retracted position, thereby positioning said articles for turning, means for moving said pull-down tube to said article engaging position in timed relation to the knitting cycle, and means for creating a suction in said turning tube to turn articles thereinto at the end of each knitting cycle.

9. In a circular knitting machine, article turning means according to claim 8 and characterized further in that said pull-down tube has an outwardly extending flange under which said first-knit elastic portions of the articles are received when said pull-down tube is in said article engaging position and which pulls said elastic portions away from said turning end as the pull-down tube slides to retracted position, and said pull-down tube is rotatable about said stationary turning tube for rotation with said articles during knitting.

iii. In a circular knitting machine, article turning means according to claim 8 and characterized further in that said pull-down tube is mounted for free rotation about said stationary turning tube in said article receiving position for rotation with the article being knit, thereby avoiding twisting of the article thereon toward said turning end.

11. In a circular knitting machine, article turning means according to claim 10 and characterized further in that said moving means retracts from said pull-down tube after said first-knit elastic portion engages said pulldown tube, allowing said pull-down tube to hang freely in said elastic portion as it slides therethrough against the restraint thereof and pulls said elastic portion away from said turning end.

12. In a circular knitting machine, article turning means according to claim 11 and characterized further in that said pull-down tube has an outwardly extending flange under which said first-knit elastic portion is received for pulling said elastic portion away from said turning end.

13. In a circular knitting machine, article turning means according to claim 12 and characterized turther in that said turning tube has a portion of reduced diameter spaced from said turning end to permit said pull-down tube to vibrate thereat and slide more readily through said elastic portion.

14. In a circular knitting machine, article turning means according to claim 13 and characterized further in that said turning end and the portion of said turning tube from said reduced portion to said turning end are of enlargcd diameter to facilitate turning the initial bulk of each article thereinto.

15. In a circular knitting machine, article turning means according to claim 8 and characterized further in that said turning tube has a portion of reduced diameter spaced from said turning end to accommodate said elastic portion during knitting of the remainder of the article, and said turning end and the portion from said reduced portion to said turning end are of enlarged diameter to facilitate turning the initial bulk of the article thereinto.

References Cited by the Examiner UNITED STATES PATENTS 2,768,516 10/1956 Moretta 66-453 X 3,159,015 12/1964 Moretta 66149 3,214,944 11/1965 Kienel 66149 MERVIN STEIN, Primary Examiner.

W. CARTER REYNOLDS, Examiner. 

1. A METHOD OF TURNING TUBULAR ARTICLES AT A CIRCULAR KNITTING MACHINE USING A STATIONARY TURNING TUBE HAVING AN OPEN TURNING END IN THE NEEDLE CYLINDER ADJACENT THE KNITTING END THEREOF AND AN EXTENSION TUBE SLIDABLE ON SAID STATIONARY TURNING TUBE, SAID METHOD COMPRISING POSITIONING SAID EXTENSION TUBE IN A RISED POSITION EXTENDING BEYOND THE TURNING END OF THE TURNING TUBE DURING THE INITIAL PORTION OF EACH KNITTING CYCLE TO PREVENT THE FIRSTKNIT PORTION OF THE ARTICLE FROM ENTERING SAID TURNING END, ALLOWING THE EXTENSION TUBE TO SLIDE DOWNWARDLY AWAY FROM SAID TURNING END BEFORE COMPLETION OF THE KNITTING CYCLE WITH SAID FIRST-KNIT PORTION BELOW THE TURNING END, CREATING A SUCTION IN SAID TURNING TUBE AT THE END OF SAID KNITTING CYCLE TO TURN ARTICLES INTO THE TURNING TUBE. 